package edu.princeton;

/*************************************************************************
 * Compilation: javac HexDump.java Execution: java HexDump < file Dependencies:
 * BinaryStdIn.java Data file: http://introcs.cs.princeton.edu/stdlib/abra.txt
 * 
 * Reads in a binary file and writes out the bytes in hex, 16 per line.
 * 
 * % more abra.txt ABRACADABRA!
 * 
 * % java HexDump 16 < abra.txt 41 42 52 41 43 41 44 41 42 52 41 21 96 bits
 * 
 * % hexdump < abra.txt
 * 
 * % od -t x1 < abra.txt 0000000 41 42 52 41 43 41 44 41 42 52 41 21 0000014
 * 
 *************************************************************************/

public class HexDump {

	public static void main(String[] args) {
		int BYTES_PER_LINE = 16;
		if (args.length == 1) {
			BYTES_PER_LINE = Integer.parseInt(args[0]);
		}

		int i;
		for (i = 0; !BinaryStdIn.isEmpty(); i++) {
			if (BYTES_PER_LINE == 0) {
				BinaryStdIn.readChar();
				continue;
			}
			if (i == 0)
				StdOut.printf("");
			else if (i % BYTES_PER_LINE == 0)
				StdOut.printf("\n", i);
			else
				StdOut.print(" ");
			char c = BinaryStdIn.readChar();
			StdOut.printf("%02x", c & 0xff);
		}
		if (BYTES_PER_LINE != 0)
			StdOut.println();
		StdOut.println((i * 8) + " bits");
	}
}
